1. Field of the Invention
This invention relates to a printing apparatus having a housing formed with a containing portion in which a power source unit for effecting printing on a printing medium is removably contained.
2. Related Background Art
Printing apparatuses for forming images such as characters on a printing medium are widely used for individual use and business purposes. It has generally often been the case that plain paper is used as the printing medium, but with the recent development of the printing technique, metal plates, fabrics, etc. have also come to be used as the printing mediums. In order to cope with such many kinds of printing mediums, there is also known a printing apparatus having a plurality of medium conveying paths, one of which is made straight.
FIG. 13 of the accompanying drawings is a cross-sectional view of the essential portions of an ink jet printing apparatus having such two conveying paths as described above.
Arrow PA indicates an automatic conveying path, and arrow PM indicates a manual conveying path. A printing medium conveyed from the automatic conveying path PA or the manual conveying path PM is conveyed onto a platen 101 and is printed there, and is conveyed out in the direction of arrow A. The reference numeral 102 designates a head cartridge, the reference numeral 103 denotes an ink tank for storing ink therein, and the reference numeral 104 designates a printing head for receiving the supply of the ink from the ink tank 103 and effecting printing. That is, the ink is discharged from the printing head 104 toward the platen 101, whereby printing is effected on the printing medium. In this case, printing is effected with the printing medium which has been guided onto the platen 101 via the automatic conveying path PA or the manual conveying path PM being held by and between a pair of guide rollers 105 and a pair of pinch rollers 106 provided forwardly and rearwardly of the platen 101.
The printing mediums to pass along the automatic conveying path PA are placed as a paper stack 109 on a receiving plate 108 disposed on a paper supply tray 107. The uppermost sheet of the paper stack 109 is picked up by a paper supply roller 110 and is conveyed onto the platen 101 via the automatic conveying route PA.
The paper supply roller 110 is supported on the paper supply tray 107 through a paper supply roller shaft 111, and during paper supply, it is rotated by a drive force obtained from drive means, not shown. Also, the receiving plate 108 is supported on the paper supply tray 107 through a pin 112, and during paper supply, it is elevated so as to approach the paper supply roller 110 by drive means, not shown, and the uppermost sheet of the paper stack 109 is adapted to resiliently contact with the paper supply roller 110.
On the other hand, the printing medium to pass along the manual conveying path PM is inserted from between a medium conveying path forming surface 114 provided on an outer case 113 as a housing and the medium conveying path auxiliary forming surface 116 of a side guide 115 for manual insertion, and passes along the manual conveying path PM and is guided onto the platen 101. The side guide 115 for manual insertion is provided in opposed relationship with a fixed side guide, not shown, in order to cooperate with this fixed sideguide to regulate the position of the printing medium in a direction perpendicular to the direction of conveyance of the printing medium passing along the manual conveying path PM. The side guide 115 for manual insertion is slidably mounted on a pair of side guide restraining portions 117 provided upstream and downstream of the medium conveying path forming surface 114, and is movable in accordance with the width of the printing medium.
A power source unit 119 formed with a connector 118 to be connected to an AC power source, not shown, is disposed in the outer case 113 located under the manual conveying path PM. Further, a circuit substrate including an element for converting an AC power source into a direct current of a predetermined voltage is contained in the power source unit 119.
In the printing apparatus as shown in FIG. 13, the manual conveying path PM is located between the paper supply tray 107 and the power source unit 119 and therefore, the total height of the printing apparatus is great, and this has led to the tendency that the installation space for the printing apparatus necessarily increases or the costs of the materials of the printing apparatus body becomes higher.
Also, there is a case where printing is effected on a printing medium of a short sheet length such as a postcard for lateral printing by way of the manual conveying path PM. When at such time, improper conveyance occurs due to some or other cause, it has been difficult to take the printing medium which has caused the improper conveyance out of the apparatus.
On the other hand, in a compact apparatus wherein particular importance is attached to portability, the mounting and dismounting of the power source unit 119 with respect to the outer case 113 are possible, and if design is made such that this can be done simply, there is the possibility of a user removing the power source unit 119 from the outer case 113 during the printing operation by mistake and causing failure of the printing operation or imparting serious damage to the printing apparatus. Therefore, generally, the printing apparatuses are designed such that a user cannot simply remove the power source unit 119 from the outer case 113.
Accordingly, when a trouble occurs to the power source unit 119 or a trouble such as jam regarding the conveyance of the printing medium occurs, there is a case where a user cannot quickly cope with the trouble, and each time a trouble occurs, the repair work by a serviceman becomes necessary, and this has led to the possibility that the convenience of use of the printing apparatus becomes very poor.
It is an object of the present invention to provide a printing apparatus of which the total height can be made small to thereby reduce the installation space and the cost of the material of a housing and in which the position of a printing medium in a direction perpendicular to the direction of conveyance of the printing medium can be stabilized to thereby improve the conveying performance therefor and moreover improve the maintenance property.
It is another object of the present invention to provide a printing apparatus with respect to which a user can simply mount and dismount a power source unit and moreover in which various troubles attributable to the power source unit being removed during the printing work by mistake can be obviated.
It is still another object of the present invention to provide a printing apparatus which has a housing formed with a containing portion in which a power source unit for effecting printing on a printing medium is removably contained and in which the power source unit has a power source portion forming a path for the printing medium.
It is yet still another object of the present invention to provide a printing apparatus which has a housing formed with a containing portion in which a power source unit for effecting printing on a printing medium is removably contained and which is provided with an opening portion formed in the housing so as to face the containing portion for putting the power source unit into and out of the apparatus therethrough, and at least a pair of restraining means formed on the housing and the power source unit for fixing the power source unit in its restrained state in the containing portion, the restrained state being manually releasable.
It is a further object of the present invention to provide a printing apparatus in which a power source unit is fixed in its restrained state in the containing portion of a housing by the engagement of restraining means and the power source unit cannot be taken out of the containing portion by simply pulling the power source unit, and when the power source unit is to be removed from the housing, the engagement of the restraining means can be released and the power source unit can be pulled out of the containing portion, and as long as the engagement of the restraining means is not released, the power source unit cannot be removed from the containing portion.
It is still a further object of the present invention to provide a printing apparatus which has a housing formed with a containing portion in which a power source unit for effecting printing on a printing medium is removably contained, and in which the power source unit has a power source portion forming a path for the printing medium, and which is provided with an opening portion formed in the housing so as to face the containing portion for putting the power source unit into and out of the apparatus therethrough, and at least a pair of restraining means formed on the housing and the power source portion for fixing the power source unit in its restrained state in the containing portion, the restrained state being manually releasable.
It is yet still a further object of the present invention to provide a printing apparatus in which a path for a printing medium is formed in a power source portion and the printing medium may be conveyed through the path, and by the engagement of engaging means, a power source unit is fixed in its restrained state in the containing portion of a housing, and the power source unit cannot be taken out of the containing portion by simply pulling the power source unit.